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//
//   http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.doris.nereids.rules.rewrite;

import org.apache.doris.nereids.rules.Rule;
import org.apache.doris.nereids.rules.RuleType;
import org.apache.doris.nereids.trees.plans.JoinType;

import java.util.stream.Stream;

/**
 * try to eliminate null aware left anti join
 * if no conjunct is nullable, null aware left anti join can be converted to left anti join safely.
 */
public class EliminateNullAwareLeftAntiJoin extends OneRewriteRuleFactory {
    @Override
    public Rule build() {
        return nullAwareLeftAntiLogicalJoin().then(antiJoin -> {
            if (Stream.concat(Stream.concat(
                            antiJoin.getHashJoinConjuncts().stream(),
                            antiJoin.getOtherJoinConjuncts().stream()),
                            antiJoin.getMarkJoinConjuncts().stream())
                    .noneMatch(expression -> expression.nullable())) {
                return antiJoin.withJoinTypeAndContext(JoinType.LEFT_ANTI_JOIN, antiJoin.getJoinReorderContext());
            } else {
                return null;
            }
        }).toRule(RuleType.ELIMINATE_NULL_AWARE_LEFT_ANTI_JOIN);
    }
}
